Eastern tent caterpillar eggs have begun hatching in Central Kentucky, just as leaf buds are swelling on wild cherry trees. While it is too early to tell what 2011 levels will be, populations have been gradually increasing over the past several years. It is also normal for insects to be very abundant in some parts of the county and moderate to low in numbers in other areas.
According to Lee Townsend, University of Kentucky College of Agriculture entomologist, the newly hatched eggs, which were laid last June, are easy to identify by the small holes tiny larva chew as they exit. In about two weeks, the tents should be about the size of a baseball and easy to spot in trees.
If control measures are needed to reduce numbers, steps should be taken before the caterpillars leave their trees.
Eastern tent caterpillars grow and develop as long as the temperature is above 37 degrees; the warmer it is, the faster they will grow.
For most landowners, damage caused by eastern tent caterpillars is mostly cosmetic. The nests are unsightly, and some defoliation of trees can occur, but long term damage to trees is rare.
On horse farms, however, the presence of eastern tent caterpillars has been linked to Mare Reproductive Loss Syndrome, and the control of caterpillars can be of significant economic importance.
Foliar sprays for caterpillar control can be made when tents are about the size of a baseball. Another option is the injection of trees with a systemic insecticide by commercial pesticide applicators or arborists
The spraying of any pesticide product into trees presents challenges, and proper precautions must be taken to protect workers from the spray materials.
For additional information about eastern tent caterpillars, please contact the Clark County Office of the University of Kentucky Cooperative Extension Service at 744-4682.